A guide to exercising in the heat of summer

Mid June is here and it’s time to prepare ourselves for our outdoor workouts (such as my adult recess class) in the summer heat. The heat and humidity, unless air quality alerts are forecasted, should not stop us from exercising outdoors. We should be prepared and have a general understanding of what is happening in our bodies on hot and humid days.

Unless properly hydrated, the heat of summer along with sweating can cause dehydration.

During exercise, a double whammy of muscular contractions and hot summer air temperatures increases our body temperature. Our primary mechanism to cool our bodies is through the evaporation of sweat on our skin. This aids in decreasing our body temperature but can also aid in dehydration on those dog days of summer. To prevent the negative effects of dehydration (heat exhaustion, heat stroke, decreased performance), we need to stay hydrated.

It’s been proven that we decrease athletic performance with a two to three percent loss of body weight (due to fluid loss). The average person loses .8 to 1.4 liters of sweat an hour with moderate exercise and 1.4 to 2 liters of sweat per hour during intense exercise. So again, stay hydrated and follow the following guide:

Drink 500ml of water 2 hours before exercise.

Drink 200 ml of water every 15-20 minutes of exercise.

Only consume sodium if your event lasts more than 60 minutes. No more than .75 grams of sodium per liter of water.

After Exercise drink 1 liter of water for every 2 lbs of body-weight loss.

And remember to use common sense. If it’s a humid 90 degree day dress in light colored and lightweight clothing, try not to exercise in the middle and hottest part of the day, wear sunscreen, acclimate to the heat before you go for your 19 mile run and remember to stay hydrated!